ONLINE RESOURCES
Electronic Supporting Material
Trophic niche width, offspring condition and immunity in a raptor species
Juan Navarro-Lopez, Pablo Vergara and Juan A. Fargallo
Online resource 1. Table showing prey mass (g) assigned to each prey item group. The
minimum identified taxon level is shown. Bibliographic sources consulted to estimate biomass
are also shown. (*) Body mass data obtained from individuals captured alive in our study area
(Campo Azálvaro, Segovia, Spain).
Prey mass
Mammals
Crocidura russula
Microtus arvalis
Birds
8.1 g , n = 310 *
31.3 g , n = 507 *
Alauda arvensis
Motacilla flava
35.0g , n = 8907 (1-3)
15.9 g , n = 194 (4)
Sturnus unicolor
Passer domesticus
Petronia petronia
Passerines (unidentified) a
84.5g , n = 2423 (5-7)
26.8 g , n = 341(8)
29.4 g , n = 6 (4)
54.0 g , n = 9 in 2006
35.0g , n = 3 in 2008
Reptiles
Chalcides striatus
Timon lepidus (adult) b
Timon lepidus (juvenile) b
Lacerta schreiberi
Podarcis hispanica
Psammodromus hispanicus
Large Lizard c
Small lizard c
Amphibians
Triturus marmoratus
Pelophylax perezi
13.3 g , n = 2 *
81.6 g , n = 32 *
43.1 g , n = 3 *
29.4 g , n = 19 *
2.0 g , n = 22 (9)
2.7 g , n = 21 *
76.0g , n = 47 in 2006
74.9 g , n = 47 in 2007
68.6 g , n = 4 in 2008
2.7 g , n = 323 in all years
9.5 g , n = 18 (10-12)
32.7 g , n= 5 *
Prey mass
Arthropods
Lycosa tarentula
1.6 g , n = 234 (13)
Gryllus campestris
Acrididae
1.1 g , n = 26*
0.6 g , n = 29 (several species included)
Tettigoniidae
Gryllotalpa gryllotalpa
Orthopterad
1.5 g , n = 14 (several species included)
2.6 g , n = 24 *
2.0 g , n = 526 in 2006
2.3 g , n = 609 in 2007
2.8 g , n = 406 in 2008
2.9 g , n = 652 in 2009
1.5 g , n = 57 (14)
0.5 g , n = 5 (14)
Mantodea
Lepidoptera
Coleoptera
Insecta (unidentified)e
Insecta (larvae)
Large prey item f
Small prey item f
Unidentified prey item g
0.6 g , n = 53 (14)
2.0 g , n = 537 in 2006
2.3 g , n = 616 in 2007
2.4 g , n = 413 in 2008
0.14 g , n = 48 (14)
46.0 g , n = 138in 2006
2.0 g , n = 659in 2006
9.4 g , n = 797 in 2006
8.0 g , n = 884 in 2007
(a) For unidentified birds (all passerines) the mean bird biomass was estimated considering the
mean body mass recorded for birds consumed in the same year as the bird prey item was
observed.
(b) In the case of Timon lepidus lizards, it was possible to determine juvenile individuals, for
which the age was took into account when estimating biomass.
(c) For some recordings, lizards could only be identified as large species (Timon lepidus or
Lacerta schreiberi) or small species (Podarcis hispanica or Psammodromus hispanicus). Biomass
was calculated as the mean body mass of both species in each group.
(d) Orthoptera species could not be determined. The mean biomass value given for this group
was calculated using the weighted mean by considering the number of field crickets, mole
crickets, Tettigonidae and Acrididae consumed in each year.
(e) Unidentified insects. The mean biomass value given for this group was calculated using the
weighted mean by considering the numbers of each insect group consumed in each year.
(f) For three prey species (two large and 1 small), only the size of the prey item could be
recorded, for which they were grouped as a large prey (mammal, bird or large lizards) or small
prey (small lizards or arthropods). Amphibians were excluded due to the low frequency of
consumption. The mean biomass value given for this group was calculated using the weighted
mean by considering the numbers of each prey group (large and small) in each year.
(g) In 19 cases the prey species, group or size could not be recorded. The mean biomass value
given for this group was calculated using the weighted mean by considering the numbers of
each prey group in each year.
References
(1) Herranz J, Traba J, Morales MB, Suárez F (2004) Nest size variation in two ground nesting
passerines, the Skylark Alauda arvensis and the Short-toed Lark Calandrella brachydactyla.
Ardea 92:209–218
(2) Hargues R, Girardot P, Ibanez F, Mourguiart P, Recarte J (2007) Migration of the Skylark
Alaudaarvensis Along the Southern French Atlantic Coast. Wildlife Biology in Practice 3 doi:
10.2461/wbp.2007.3.11
(3) Corbacho C, Morán R, Villegas MA (2005) La alimentación del Aguilucho Cenizo Circus
pygargusen relación a los usos del suelo en áreas pseudoestepáricas de Extremadura (SO
península Ibérica). Ardeola 52: 3-19
(4) Cramp S (1994) The Birds of the Western Palearctic, vol. IX. Buntings and new world
warblers. Oxford: Oxford University Press
(5) LezanaL, Miranda R, Campos F, Peris SJ (2000) Sex differentiation in the spotless starling
(Sturnus unicolor, Temminck 1820). Belg J Zool 130:139-142
(6) Veiga JP, Polo V (2011) Estornino negro – Sturnus unicolor. Enciclopedia Virtual de los
Vertebrados Españoles. Salvador, A., Morales, M. B. (Eds.). Museo Nacional de Ciencias
Naturales, Madrid
(7) Gil D, Bulmer E, Celis P, Puerta M (2008) Increased sibling competition does not increase
testosterone or corticosterone levels in nestlings of the spotless starling (Sturnus unicolor).
Horm Behav 54:238-243 doi: 10.1016/j.yhbeh.2007.11.013
(8) Förschler MI, Geiter O (2010) Morphological shifts in the house sparrow Passer domesticus
on Helgoland: insular syndrome or founder effects? Ornis Fenn 87:93-98
(9) Carretero MA, Llorente GA (1993). Ecología térmica y actividad en una población costera de
Psammodromus hispanicus. Revista Española de Herpetología, 7:21-32
(10) Jehle R, Arntzen JW (2000) Post-breeding migrations of newts (Triturus cristatus and T.
marmoratus) with contrasting ecological requirements. J Zool 251:297-306 doi:
10.1111/j.1469-7998.2000.tb01080.x
(11) Diego-Rasilla FJ (2000) Malformaciones en una población de Triturus marmoratus. Boletín
de la Asociación Herpetológica Española 11:88-89
(12) Diego-Rasilla FJ, Luengo RM, Rodríguez-García L (2007) Triturus marmoratus (Marbled
Newt). Limb abnormalities. Herpetological Review 38:68
(13)Moya-Laraño J, Orta-Ocaña JM, Barrientos JA, Bach C, Wise DH (2002) Territoriality in a
cannibalistic burrowing wolf spider. Ecology 83:356–361 doi: 10.1890/00129658(2002)083[0356:TIACBW]2.0.CO;2
(14) Bustamante JM (1985) Alimentación del Ratonero común (Buteo buteo L: 1758) en el
norte de España. Doñana, Acta Vertebrata 12: 51-62
Online Resource 2
Results: Inter-annual variation in kestrel diet
The consumption of mammals varied significantly among years (GENMOD, 21,3 = 384.2, P <
0.001) being significantly highest in 2008, followed by 2009 and 2006-07 having the lowest
values (Online Resource 3 and 4). Contrasts showed significant differences between all pairwise annual comparisons (all P < 0.001) except for 2006-07 (P = 0.107). Results of the model
are shown in Table S3. In the case of birds no significant inter-annual variation was observed
(GENMOD, 21,3 = 3.6, P = 0.309, (Online Resource 3 and 4). Reptiles were also differently
consumed among years (GENMOD, 21,3 = 84.6, P < 0.001), being the highest consumption in
2006-07 and the lowest in 2008-09 (Online Resource 3 and 4). Contrasts showed significant
differences between all pair-wise annual comparisons (all P< 0.001) except for 2006-07 and
2008-09 (both P > 0.11). Results of the model are shown in Online Resource 4. Amphibians
were also differently preyed among years (GENMOD, 21,3 = 10.5, P < 0.001), being more
preyed in 2008 and 2009 than in 2006 and 2007 (Online Resource 3 and 4). Contrasts showed
significant differences in 2006-2008, 2007-2009 and 2006–2009 comparisons (all P < 0.040),
but not for the remaining pair-wise annual comparisons (all P > 0.12). Finally, the consumption
of arthropods was also different among years (GENMOD, 21,3 = 92.6, P < 0.001) being 2008 the
year in which arthropods were less frequently consumed (Online Resource 3 and 4). Contrasts
showed significant differences between 2008 and the other three years (all P < 0.001).
Online Resource 3. Total numbers (N), percentage and biomass of prey items delivered by common kestrel parents to the nest in each study year (20062009). The minimum identified taxon level is shown. Similar superscript letters within the same taxonomic group indicate no significant inter-annual
difference in the frequency of consumption by kestrels ( = 0.05).
2006
2007
2008
2009
N (%)
% Biomass
N (%)
% Biomass
N (%)
% Biomass
N (%)
% Biomass
Mammals
Crocidura russula
Microtus arvalis
56 (6.4)a
0 (0)
56 (6.4)
22
0
22.0
81 (9)a
0 (0)
81 (9.3)
38.6
0
38.6
329 (39.6)b
21 (2.5)
308 (37.1)
83.3
1.5
81.8
158 (17.2)c
32 (3.5)
126 (13.7)
44.4
2.8
41.6
Birds
Alauda arvensis
Motacilla flava
Sturnus unicolor
11
3
1
4
(1.2)a
(0.3)
(0.1)
(0.5)
7.5
1.3
0.2
4.3
5 (0.56)a
0 (0)
1 (0.1)
3 (0.3)
4.5
0
0.2
3.9
5 (0.6)a
3 (0.4)
0 (0)
0 (0)
1.5
0.9
0
0
8 (0.9)a
1 (0.1)
0 (0)
6 (0.7)
6.2
0.4
0
5.5
Passer domesticus
Petronia petronia
Passerines (unidentified)
1 (0.1)
0 (0)
2 (0.2)
0.3
0
1.4
1 (0.1)
0 (0)
0 (0)
0.4
0
0
0 (0)
0 (0)
2 (0.2)
0
0
0.6
0 (0)
1 (0.1)
0 (0)
0
0.3
0
Reptiles
Chalcides striatus
Timon Lepidus
Lacerta schreiberi
192 (21.9)a
24 (2.7)
42 (4.8)
5 (0.6)
52.8
4.0
39.2
1.8
184 (20.5)a
32 (3.6)
27 (3)
4 (0.4)
34.1
1.3
24.9
1.8
75 (8.9)b
12 (1.4)
3 (0.4)
1 (0.1)
6
1.4
1.8
0.3
96 (10.5)b
31 (3.4)
32 (3.5)
1 (0.1)
33.4
4.5
27.7
0.3
Podarcis hispanica
Psammodromus hispanicus
2 (0.2)
113 (12.9)
0.1
3.8
3 (0.3)
116 (12.9)
0.1
4.8
2 (0.2)
55 (6.6)
0.0
1.3
1 (0.1)
31 (3.4)
0.0
0.9
Large Lizard
4 (0.5)
3.8
1 (0.1)
0.1
2 (0.2)
1.2
0 (0)
0.0
Small lizard
2 (0.2)
0.1
1 (0.1)
1.1
0 (0)
0.0
0 (0)
0.0
Amphibians
Triturus marmoratus
Pelophylax perezi
0 (0)a
0 (0)
0 (0)
0
0
0
1 (0.1)a
0 (0)
1 (0.1)
0.5
0
0.5
4 (0.5)b
3 (0.4)
1 (0.1)
0.6
0.3
0.3
6 (0.7)b
0 (0)
6 (0.7)
2.1
0
2.1
Arthropods
Lycosa tarentula
Gryllus campestris
Acrididae
Tettigoniidae
G. gryllotalpa
Orthoptera (unidentified)
Mantodea
Lepidoptera
595 (68.2)a
12 (1.4)
182 (20.8)
15 (1.7)
16 (1.8)
313 (35.9)
4 (0.5)
0 (0)
1 (0.1)
14.4
0.2
2.5
0.1
0.3
10.2
0.1
0.0
0.0
625 (69.5)a
5 (0.6)
86 (9.6)
15 (1.7)
3 (0.3)
505 (56.2)
1 (0.1)
1 (0.1)
0 (0)
22.2
0.1
1.4
0.1
0.1
20.0
0.1
0.1
0.0
417 (50.3)b
0 (0)
48 (5.8)
4 (0.5)
0 (0)
354 (42.7)
0 (0)
0 (0)
0 (0)
8.7
0.0
0.5
0.0
0.0
8.1
0
0.0
0.0
653 (70.9)a
0 (0)
187 (20.3)
69 (7.5)
15 (1.6)
381 (41.4)
0 (0)
0 (0)
0 (0)
13.7
0.0
2.2
0.5
0.2
10.8
0
0.0
0.0
Coleoptera
Insecta (unidentified)
5 (0.6)
41 (4.7)
0.0
1.0
4 (0.4)
2 (0.2)
0.1
0.1
1 (0.1)
4 (0.5)
0.0
0.1
0 (0)
0 (0)
0.0
0.0
Insecta (larvae)
6 (0.7)
0.0
3 (0.3)
0.1
6 (0.7)
0.0
1 (0.1)
0.0
Large prey item
Small prey item
2 (0.2)
1 (0.1)
1.1
0.1
0 (0)
0 (0)
0.0
0.0
0 (0)
0 (0)
0.0
0.0
0 (0)
0 (0)
0.0
0.0
Unidentified prey item
16 (1.8)
1.9
3 (0.3)
0.4
0 (0)
0
0 (0)
0
Total prey items
873
966
831
921
Online Resource 4. Logistic model (GENMOD) results on the inter-annual variation in the
frequency of prey taxon consumption by common kestrels Falco tinnunculus. Degrees of
freedom (D.F.) Estimates, standard errors (S.E.), 95% confidence intervals for the predicted
value of the means (Wald 95% CI), Wald chi-squared value (Wald 2) and the probability of
obtaining a Wald chi-squared statistic greater than that observed given that the true
parameter is 0 (Pr > 2) are shown.
Wald 2
Pr > 2
(-1.4260, -0.7852)
(-1.1013, -0.5317)
(0.9315, 1.3727)
45.75
31.57
104.76
-
<0.001
<0.001
<0.001
-
0.4671
0.5720
0.5721
-
(-0.5395, 1.2914)
(-1.6423, 0.5998)
(-1.4912, 0.7514)
-
0.65
0.83
0.42
-
0.4209
0.3621
0.5180
-
0.8850
0.7041
-0.1595
-
0.1353
0.1354
0.1621
-
(0.6198, 1.1501)
(0.4387, 0.9696)
(-0.4773, 0.1582)
-
42.78
27.03
0.97
-
<0.001
<0.001
0.3252
-
1
1
1
-25.0474
-1.8450
-0.3043
-
114843
1.0811
0.6473
-
(-225114, 225064)
(-3.9639, 0.2740)
(-1.5730, 0.9643)
-
0.00
2.91
0.22
-
0.9998
0.0879
0.6382
-
1
1
1
-0.1296
-0.2847
-0.8834
1.0000
0.1027
0.0990
0.1004
0.0000
(-0.3309, 0.0716)
(-0.4787, -0.0907)
(-1.0801, -0.6866)
(1.0000, 1.0000)
1.59
8.28
77.44
-
0.2067
0.0040
<0.001
-
Term
Mammals
d.f.
Estimate
S.E.
2006
2007
2008
2009
Birds
1
1
1
-
-1.1056
-0.8165
1.1521
-
0.1635
0.1453
0.1126
-
2006
2007
2008
2009
Reptiles
1
1
1
0.3759
-0.5212
-0.3699
-
2006
2007
2008
2009
Amphibians
1
1
1
2006
2007
2008
2009
Arthropods
2006
2007
2008
2009
Scale
0
Wald 95% CI
Online Resource 5. Linear mixed models (LMM) of prey biomass and prey diversity (ShannonWiener Index; SWI) consumed by common kestrels Falco tinnunculus from 2006 to 2009.
Clutch size was included as a covariate and year as a fixed factor. Interaction between clutch
size and year is tested. Nest location was included as a random factor. Model selection was
based on the Akaike’s Information Criterion corrected for small sample sizes (AICc). Delta
(ΔAICc) and weights (wAICc) for each AICc are also shown. ld = laying date, cs = clutch size, ye =
year, pb = prey biomass.
Model
AICc
ΔAICc
wAICc
Prey biomass
1) cs
2) cs + ye
3) cs + ye + cs*ye
4) ye
730.8
733.0
736.2
740.0
0
2.2
5.4
9.2
0.71
0.24
0.04
0.01
Prey diversity (SWI)
1) cs + ye + cs*ye
2) cs + pb + ye
3) ye
4) cs + ye
5) cs + pb
54.4
57.5
61.8
62.9
71.1
0
3.1
7.4
8.5
16.7
0.80
0.19
0.03
0.01
0.00
Online Resource 6. Five best linear mixed-models (LMM) of fledgling body mass and immune
response to PHA of common kestrels Falco tinnunculus from 2006 to 2009. Laying date, clutch
size, number of fledglings at the age of 26 days old, fledgling wing length, fledgling weight,
prey diversity SWI (Shannon-Wiener Index; SWI) and biomass of prey consumed were included
as covariates. Fledgling sex and year as fixed factors and kestrel nest as a random factor.
Model selection was based on the Akaike’s Information Criterion corrected for small sample
sizes (AICc). Delta (ΔAICc) and weights (wAICc) for each AICc are also shown. ld = laying date, cs
= clutch size, nf = number of fledglings, wl = wing length, fbm = fledgling body mass, swi = prey
diversity (SWI), pb = prey biomass, sx = sex, ye = year.
Model
AICc
ΔAICc
wAICCc
Fledgling body mass
1) wl + swi + sx + ye
2) cs + wl + swi + sx + ye
3) cs + wl + swi + sx + ye + cs x ye
4) wl + sx + ye
5) cs + wl + swi + bm + sx + ye + cs x ye
3125.8
3125.9
3128.2
3130.2
3130.4
0
0.1
2.4
4.4
4.6
0.41
0.39
0.11
0.05
0.04
Immune response to PHA
1) fbm + swi + sx + ye
2) fbm + swi + pb + sx + ye
3) fbm + pb + sx + ye
4) fbm + swi + pb + sx
5) fbm + swi + sx
4198.9
4200.8
4205.4
4216.6
4217.0
0
1.9
6.5
17.7
18.1
0.70
0.27
0.03
0.00
0.00